Tool for hydraulically displacing well materials



Jan. 20', 1953 w. A. MAXWELL 'ET AL 2,626,177

TOL FOR HYDRAULICALLY DISPLACING WELL MATERIALS Filed May 5. 1947 am Mlnz'plhxh/LL @anlrosnvnup IN VEN TORS BY m Hr mfp/vtr Patented Jan. 20, 1953 TOOL FOR HYDRAULICALLY DISPLACING WELL MATERIALS Wilber A. Maxwell, Houston, Tex., and John A. Engstrand, Los Angeles, Calif., assignors to Grant Oil Tool Company, Los Angeles, Calif., a corporation of California Application May 5, 1947, Serial No; 746,038

Claims.

This invention relates to improved apparatus for the displacement or recovery of solid materials and bodies in oil wells, and having as a general mode of operation such displacement or recovery by the creation of a uid surge resulting from the opening of a low pressure chamber into communication with the displacement Zone.

Heretofore this same type of operation has been extensively employed in the use of suctiontype bailers and cleaners in various forms utilizing normally closed chambers lowered within the hydrostatic Well uid column to the bottom of the well or other location at which solids are to be displaced, the chambers having closures adapted to be suddenly opened to admit to the chambers hydraulic material-displacing surges which occur under pressures corresponding to the hydrostatic head oi the well liquid column standing above the displacement zone at which the cham-ber inlet ordinarily is located. In instances where the extent of the hydrostatic column above the displacement is great, the differentials between the hydrostatic and empty charge receiving chamberl pressures are correspondingly great, the result being that when the chamber is avoidable for the reason that the hydrostatic.

column-chamber pressure differential and the fluid flow or surge proportionate to that difierential have been xed because the displacement zone and the chamber inlet have been under virtually the same hydrostatic pressure, and the chamber constitutes a closed empty zone under atmospheric pressure.

The primary object of the present invention is to avoid the abovementioned consequences of violent pressure surges in the displacement or recovery of solid materials from a well, by prov viding for the maintenance of any desired difierential between the chamber pressure and the hydrostatic displacement zone pressure, and in so doing to diminish to whatever extent desired the violence of the surge that would ordinarily occur at the displacement zone depth employing the conventional methods and equipment.

More speciiically, the invention contemplates lowering in the well a normally closed chamber communicable with the displacement zone but positionable above that zone a distance sumciently remote therefrom that the elective hydrostatic pressure of the fluid tending to enter the chamber will be less than the hydrostatic pressure on the displacement zone, to a degree such that when the chamber is opened, the consequent liquid in-surge will have no greater activity or violence than that necessary for movement of solids in the displacement zone. As will be apparent, the chamber position may be at any submergence depth in the hydrostatic column, so that the effective column-chamber pressure differential may be selected or predetermined as desired to create suiiicient surge for displacement of the solids, while insuring against a surge violence productive of adverse results.

A further object of the invention is to provide for simple incorporation of the charge receiving chamber and its communication with the displacement zone, in a drill pipe String including a lower section extending down to the displacement zone, and an upper section containing the charge receiving chamber and extending to a depth determinative of the chamber inlet fluid pressure and the activity of the surge to be communicated to the displacement zone. As will appear, the pipe string sections are so connected as to have relative movement by virtue of which the charge receiving chamber is opened, and to permit the well iluid to rise to chamber height within the lower section.

Also contemplated is the provision of a tool on the pipe string for receiving and retaining solid materials displaced by -the liquid surge.' For this Y purpose I may employ a tool of the so-called junk basket type carried by the lower pipe string section and through which the displacement zone is in communication with the charge receiving chamber.

The abovementioned as well as various additional features and objects of the invention will be more fully explained in the following detailed description of the illustrative embodiment shown I I and a relatively vertically movable upper section l2 extending to the ground surface. As will appear, the upper section of the pipe string, or at least the lower portion thereof, constitutes a normally closed low pressure chamber communicable with a lower zone at which the displacement of material is to be eiected, and so positioned in the well that the effective pressure of the hydrostatic well fluid column tending to enter the chamber upon its opening, may be any amount less than the hydrostatic column pressure at the displacement zone, depending upon the depth at which the chamber opening, i. e. the bottom portion of the pipe string section I2, is positioned in the well. Thus it will be understood that the well bore will contain a hydrostatic column extending above the bottom portion of the pipe string section I2, and that the length of the latter may be varied as desired, to give any predetermined or selected pressure differential inside and outside the low pressure chamber I3 when the latter is opened. The displacement zone I4 is shown to be at the bottom of the well, and may be assumed to contain displaceable solids of any character, and particularly metallic or other objects retrieveable in a so-called junk basket type of fishing tool, for removal to the ground surface.

The pipe string sections II and I2 are shown to be interconnected by a telescopic joint assembly generally indicated at I5, and including a closure for the bottom of the chamber I3, and means operable by relative vertical movements of the sections to open the closure. Referring to Fig. 2, section I2 is connected by tubular coupling I6 and the threaded joint at I'I with a sleeve I8, the latter having a counterbore ISI forming an annular shoulder 20. In the broad contemplation of the invention, the chamber I3 may have any suitable type of bottom closure 2| capable of being opened by manipulation of the pipe string to admit well fluid to the chamber. As illustrative, the closure is shown to consist of a frangible disc 22 confined between gaskets 23 by a bushing 24 screwed into the lower Y threaded end of the coupling I6, the bushing having a frustro-conical surface 25.

Sleeve I8 is connected with the top coupling end 26 of the lower pipe string section II by a tubular mandrel 2'! threaded at 28 into the coupling and having splines 29 extending through ways 30 in the sleeve, see Fig. 4, the splines permitting transmission of rotation from the upper to the lower string section as for turning the fishing tool into the bottom sand. The mandrel 2l has an enlarged diameter disc breaker head SI engageable against shoulder 23 to suspend the string section below, and containing one or more lateral openings 32 through which fluid may pass upwardly from section II into the space 33. Head BI may carry the O typev seal rings 3II to prevent uid leakage along the head. Upon downward movement of vthe upper section I2 relative to the lower section II, the disc 22 is fractured by impact against the pointed breaker head 3Ia, relative movement of the breaker toward the disc being limited by engagement of the lower end of the coupling I8 with tool joint 26. Full opening of the chamber inlet may be eilected by raising the seat 25 from the breaker after the disc is ruptured. In order to assure quick and complete rupturing of the disc, impacting of the latter against the breaker may be caused to occur under substantial load from above, as by using a shear pin 35 projecting into and engageable with the end of the mandrel recess 35 until the superposed load is sufliciently Cil great to shear the pin, at which point the dise is suddenly dropped against the breaker.

The lower string section II may carry any suitable form of tool adapted to receive and retain solids displaced from the zone I4, as a result of an upward fluid surge created by opening the chamber I3. Typically the tool |36 is shown to comprise a tubular body 31 connected by coupling 33 to the pipe string and having a bottom coring edge 39 capable of penetrating the sand in the bottom of the well. The body may contain one or more sets of retainers, such as the circular arrangement of radially deflectible fingers 4B shown in Fig. 3, past which the solids are carried upwardly by the fluid surge to thereafter be retained by the finger assembly.

Suitable provision may be made for venting gas or air from the top of the lower pipe string section II as the latter is run down through the hydrostatic column? as by means of a valvular gas release preventing in-ow to the string when the low pressure chamber is opened. Referring to Fig. 2, coupling 26 may contain a pressure release, generally indicated at 4I! comprising a ball valve 6I contained in bore 42 and seating against shoulder 43 to control the gas escape from the string section II through passages 4d and 45. Opening of the valve is resisted by coil spring t, the compressive force of which is adjustable by plug M to maintain any desired seating thrust against the valve. As illustrative, the pressure release may be set to permit opening of the valve at a gas pressure of yaround lbs. per sq. in.

In operation the apparatus is run into the well in the condition illustrated in Figs. l and 2 with the connection I 5 located at a remote elevation above the displacement zone I4. As illustrative, depending upon the desired pressure diferential conditions, the low pressure chamber inlet 48 may be located in excess of 500 to 1000 feet above the displacement zone. As the equipment is lowered down through the hydrostatic column of well fluid, the latter may be permitted to rise within the lower string section II to the height of the disc 22 (when the latter is lowered below the top of the hydrostatic column) because of the capacity of the pressure release 4I! to open and vent gas or air from the lower string section. Assuming the tool I35 to be bottomed in the sand, downward movement of the upper string section I 2 causes the disc to be impacted and ruptured against the breaker head, as described, whereupon the chamber I3 is opened to admit a high velocity surge of well fluid from the displacement zone I@ upwardly through the lower string section. As will be understood, however, the effective pressure diierential under which the iiuid enters the chamber, is the difference between the normal internal pressure of the chamber and the hydrostatic pressure of the well fluid column kstanding above the chamber inlet. Thus, though directly communicated to the displacement zone I d, the action or magnitude of the surge will be far less than that which ordinarily results from lthe opening of a chamber at the depth of the displacement zone and with consequent excessive disturbances in the well.

We claim:

1. Apparatus for displacing material at a location in a well containing a hydrostatic column, that includes a vertically extending continuous tubular pipe string lowered in the well to said location and comprising upper and lower sections, said lower section communicating with the well liquid at said location and containing a body of liquid extending upwardly high above said loca` tion, a closure in the pipe string at a remote position above said location and initially closing a lower inlet end of said upper section against entry of the well liquid from said lower section, said inlet when opened being communicable with said location through said lower section of the pipe string, the pressure of the column liquid tending to enter said upper section being reduced by said liquid in the lower section to a value exceeding the pressure inside the upper section by an amount substantially less than the hydrostatic column pressure at the depth of said location, said pipe string including a joint interconnecting said sections for relative vertical movement, a member movable relative to one of said sections in response to relative vertical movement of the sections, said member being positioned to upon said movement act against and open said closure to thereby create a surge of liquid upwardly through said lower section from said location, said lower section comprising a large number of pipe stands connected in an end to end series and extending downwardly beneath the upper section inlet and beneath said last mentioned member toward said location, and a tool carried at said location by a bottom one of said stands for receiving well material displaced by the surge.

2. Apparatus as recited in claim 1, in which said pipe string contains a vent opening placing an upper portion of said lower section in communication with the well at the outside of the pipe string to vent gas from the lower section and thereby cause the lower section to ll with well liquid to substantially the height of the upper section.

3. Apparatus as recited in claim 2, including a check valve preventing fluid inflow through said vent opening and into said lower section of the pipe string.

4. Apparatus for displacing material at a location in a well containing a hydrostatic column, that includes a vertically extending continuous tubular pipe string lowered in the well to said location and comprising upper and lower sections, said lower section communicating with the well liquid at said location and containing a body of liquid extending upwardly high above said location, a closure in the pipe string at a remote position above said location and initially closing a lower inlet end of said upper section against entry of the well liquid from said lower section, said inlet when opened being communicable with said location through said lower section of the pipe string, the pressure of the column liquid tending to enter said upper section being reduced by said liquid in the lower section to a Value exceeding the pressure inside the upper section by an amount substantially less than the hydrostatic vcolumn pressure at the depth of said location,

said pipe string including a joint interconnecting said sections for relative vertical movement, said closure being frangible and carried by one of said sections, and a breaker carried by the other section and acting to engage and break the frangible closure upon relative vertical movement of the sections, said lower section comprising a large number of pipe stands connected in an end to end series and extending downwardly beneath the upper section inlet and beneath said breaker toward said location, and a tool carried at said location by a bottom one of said stands for receiving well material displaced by the surge.

5. Apparatus for displacing material at a location in a well containing a hydrostatic column, that includes a vertically extending continuous tubular pipe string lowered in the well to said location and comprising upper and lower sections, said lower section communicating with the well liquid at said location and containing a body of liquid extending upwardly high above said location, a frangible disc seating upwardly within the lower portion of said upper section at a remote position above said location and initially closing a lower inlet end of said upper section against entry of the well liquid from said lower section, said inlet when opened being communicable with said location through said lower section of the pipe string, the pressure of the column liquid tending to enter said upper section being reduced by said liquid in the lower section to a value exceeding the pressure inside the upper section by an amount substantially less than the hydrostatic column pressure at the depth of said location, said apparatus including a joint interconnecting the sections for relative vertical movement, and a breaker carried by the lower section and acting to engage and break the disc upon downward relative movement of the upper section, to thereby create a surge of liquid upwardly through said lower section from said location, said lower section comprising a large number of pipe stands connected in an end to end series and extending downwardly beneath the upper section inlet and beneath said breaker toward said location, and a tool carried at said location by a bottom one of said stands for receiving well material displaced by the surge.

WILBER A. MAXWELL. JOHN A. ENGSTRAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,968,282 Cavins July 3l, 1934 2,090,616 Erwin Aug. 24, 1937 2,118,458 Cavins May 24, 19-38 2,884,090 Hartsell Sept. 4, 1945 

